In a nutshell it is the close planting of varieties that enhance each other’s growth, or protect each other from pests and insects. The first and foremost rule of companion planting is diversity. If all the plants are the same they are competing for exactly the same nutrients and can often end up having the same pest problems. However if you group different types of plants together you bring a balanced ecosystem to your garden, allowing nature to do its job. There are many aspects to effective companion planting; here is a summary with the best plants and techniques to use along with a quick explanation on how it all works.

Confuse pests and insects by using strong smelling plants, and a range of colours and shapes.Pest and insects find your plants by both sight and smell so creating a diversity of plants can really confuse them and they may go somewhere else to get a quick bite to eat. Masking plants are the best ones to use to repel insects. These are plants that produce strong, volatile oils and scent which actually mask the plants that harmful insects may be looking for. It is almost like there is a “fragrant cloud” that surrounds the masking plant and those nearby which ideally should deter those unwanted insects. Marigolds, lavender, garlic, basil, sage and rosemary are great examples of masking plants.

Plant the right seeds to help assist the growth of other plants.Some plants such as Parsley and Lemon Balm are considered to have a positive effect on a wide range of nearby plants. These plants emit chemicals from their roots which act as a growth stimulant for other varieties. These small plants can make great additions to otherwise bare gaps in your garden and are also great planted around the boarders of your garden. There are other plants out there that are excellent at fixing nitrogen from the atmosphere because of the bacteria within their root system. Peas, beans and other legumes are perfect examples of this, as they use the nitrogen to help themselves grow and once they die and are dug back into the soil they release the fixed nitrogen making it available to other plants which in turn helps to fertilise the soil.

Invite GOOD insects, birds and wildlife into your garden.Native birds, bees and butterflies can provide an essential function in our gardens ecosystem by assisting in pollination and the control of insects. Chives, coriander, dill and garlic are some examples to use; there are also some flowers which work well such as cosmos, calendula, lavender, salvia and nasturtiums.

Create suitable micro-climates for your plants.Plants come in all different shapes and sizes, some need full sun and some don’t. Why not use this to your advantage? For example, lettuce and celery don’t perform well with too much afternoon summer sun, whereas capsicums and eggplant love full sun. So why not plant your lettuce among or to the south east of the capsicums and eggplants that way they each get the right amount of sun.

What sort of root system does your plant have?You will find that if you sow all of the same plants near each other they will all end up competing for exactly the same water and nutrients at the same root depth. Try sowing varieties that have different root systems that way they aren’t searching for nutrients in the same areas.By sowing one row of lettuce, one row of carrots and then a row of tomatoes you would be allowing each of these to access their own nutrients.